The central aim of this secondary analysis of the National Institute of Child Health and Human Development Study of Early Child Care (NICHD SECC) data set is to investigate individual and contextual factors that contribute to risk and resilience in anxious solitary children (children who display elevated shy, solitary behavior among peers) from birth through first grade. Although research has demonstrated that anxious solitary children differ from other children on a host of interpersonal, emotional, and life-transition outcomes, they show a great deal of heterogeneity in adjustment. Whereas the majority of prior research has documented between-group differences, the proposed series of studies examines within-group differences, including individual and contextual factors that forecast differential adjustment trajectories among anxious solitary children. The large size of the NICHD SECC data set (N = 1364, 48% female) is uniquely suited to examining differences among anxious solitary children. Recent research has identified peer relations difficulties in the early school years as a factor that forecasts divergent adjustment trajectories among anxious solitary children over the course of middle childhood (Gazelle & Ladd 2003). The proposed series of studies focus on the period prior to and including the early school years (birth through first grade), permitting investigation of early childhood factors that may moderate anxious solitary children' s risk for peer relations difficulties in the early school years. Specifically, analyses will examine 1) multi-level individual and contextual characteristics in early childhood as moderators of anxious solitary children's risk for peer rejection in the early school years, 2) concurrent classroom emotional climate as a moderator in the relationship between early childhood history of anxious solitude and peer rejection in first grade, 3) peer rejection in kindergarten as a moderator in the relationship between early childhood history of anxious solitude and emotional difficulties in fast grade, 4) stability of anxious solitude across school and child care contexts as a function of the peer rejection experienced in these contexts, and 5) multi-level individual and contextual predictors of stability of anxious solitude across time.